当前位置：
X-MOL 学术
›
J. Phys. Chem. A
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Kinetics of the Reactions between the Criegee Intermediate CH2OO and Alcohols
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2017-12-29 00:00:00 , DOI: 10.1021/acs.jpca.7b09773 Sara V. Tadayon 1 , Elizabeth S. Foreman 1 , Craig Murray 1
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2017-12-29 00:00:00 , DOI: 10.1021/acs.jpca.7b09773 Sara V. Tadayon 1 , Elizabeth S. Foreman 1 , Craig Murray 1
Affiliation
|
Reactions of the simplest Criegee intermediate (CH2OO) with a series of alcohols have been studied in a flash photolysis flow reactor. Laser photolysis of diiodomethane at 355 nm in the presence of molecular oxygen was used to produce CH2OO, and the absolute number densities were determined as a function of delay time from analysis of broadband transient absorption spectra obtained using a pulsed LED. The kinetics for the reactions of CH2OO with methanol, ethanol, and 2-propanol were measured under pseudo-first-order conditions at 295 K, yielding rate constants of (1.4 ± 0.4) × 10–13 cm3 s–1, (2.3 ± 0.6) × 10–13 cm3 s–1, and (1.9 ± 0.5) × 10–13 cm3 s–1, respectively. Complementary ab initio calculations were performed at the CCSD(T)/aug-cc-pVTZ//CCSD/cc-pVDZ level of theory to characterize stationary points on the reaction enthalpy and free energy surfaces and to elucidate the thermochemistry and mechanisms. The reactions proceed over free energy barriers of ∼8 kcal mol–1 to form geminal alkoxymethyl hydroperoxides: methoxymethyl hydroperoxide (MMHP), ethoxymethyl hydroperoxide (EMHP), and isopropoxymethyl hydroperoxide (PMHP). The experimental and theoretical results are compared to reactions of CH2OO with other hydroxylic compounds, such as water and carboxylic acids, and trends in reactivity are discussed.
中文翻译：
Criegee中间体CH 2 OO与醇之间反应的动力学
在闪蒸光解流反应器中研究了最简单的Criegee中间体（CH 2 OO）与一系列醇的反应。在分子氧存在下，在355 nm下对二碘甲烷进行激光光解产生CH 2 OO，并通过分析使用脉冲LED获得的宽带瞬态吸收光谱，确定绝对数密度作为延迟时间的函数。在伪一级反应条件下于295 K下测量CH 2 OO与甲醇，乙醇和2-丙醇反应的动力学，其速率常数为（1.4±0.4）×10 –13 cm 3 s –1， （2.3±0.6）×10 –13 cm 3 s分别为–1和（1.9±0.5）×10 –13 cm 3 s –1。互补的从头算是在CCSD（T）/ aug-cc-pVTZ // CCSD / cc-pVDZ理论水平上进行的，以表征反应焓和自由能表面上的固定点，并阐明热化学和机理。反应在约8 kcal mol –1的自由能垒上进行，形成双生的烷氧基甲基氢过氧化物：甲氧基甲基氢过氧化物（MMHP），乙氧基甲基氢过氧化物（EMHP）和异丙氧基甲基氢过氧化物（PMHP）。将实验和理论结果与CH 2的反应进行了比较讨论了OO与其他羟基化合物（例如水和羧酸）的反应性趋势。
更新日期：2017-12-29
中文翻译：
Criegee中间体CH 2 OO与醇之间反应的动力学
在闪蒸光解流反应器中研究了最简单的Criegee中间体（CH 2 OO）与一系列醇的反应。在分子氧存在下，在355 nm下对二碘甲烷进行激光光解产生CH 2 OO，并通过分析使用脉冲LED获得的宽带瞬态吸收光谱，确定绝对数密度作为延迟时间的函数。在伪一级反应条件下于295 K下测量CH 2 OO与甲醇，乙醇和2-丙醇反应的动力学，其速率常数为（1.4±0.4）×10 –13 cm 3 s –1， （2.3±0.6）×10 –13 cm 3 s分别为–1和（1.9±0.5）×10 –13 cm 3 s –1。互补的从头算是在CCSD（T）/ aug-cc-pVTZ // CCSD / cc-pVDZ理论水平上进行的，以表征反应焓和自由能表面上的固定点，并阐明热化学和机理。反应在约8 kcal mol –1的自由能垒上进行，形成双生的烷氧基甲基氢过氧化物：甲氧基甲基氢过氧化物（MMHP），乙氧基甲基氢过氧化物（EMHP）和异丙氧基甲基氢过氧化物（PMHP）。将实验和理论结果与CH 2的反应进行了比较讨论了OO与其他羟基化合物（例如水和羧酸）的反应性趋势。
京公网安备 11010802027423号